This invention relates generally to improvements in internal engine combustion, and more particularly to improvements in control of combustion gas flow in combustion chambers, and also to equalization of air or gas (fuel and air mixture) supply to the multiple combustion chambers in an engine.
There is need for such improvements in combustion gas flow within combustion chambers, and for distribution of pressurized air in equal quantities to such combustion chambers, for example to obtain better efficiency, greater power output, and smoother running of engines and reduced emissions.
It is a major object of the invention to provide such improvements, as referred to.
Basically, the invention is embodied in an internal combustion engine that has multiple cylinders, each cylinder defining a cylinder wall, and having a cylinder head, there being a piston movable axially within each cylinder to define a combustion zone between the piston top and the cylinder head, each cylinder having intake porting. In this combination the invention provides:
a) a manifold for delivering air to said combustion zones, via the intake porting at each cylinder,
b) said manifold including gas induction ducts, which are configured with branching to deliver substantially the same quantity of air to each said porting.
As will be seen, the ducts typically include branches, each branch supplying gas such as air to two of the intake ports.
In this regard, a standard 6-cylinder engine will have each cylinder receiving different amounts of air, when the air manifold is supplied with air at one entry point. The normal engine is supplied with 10 to 15 percent over supply of fuel in order to supply sufficient combustible mixture to all cylinders.
In the present invention, when the air supply from a turbocharger is changed from one supply duct or tube to three supply tubes, the manifold is considered as looped. One air supply duct or tube will supply air to two valves. Each valve will receive the same amount of air at the same air pressure under these conditions.
With the looped induction system used in an engine, all intake valves at the cylinders receive the same amount of air. The fuel supply can be reduced from the 10 to 15 percent over supply level to the exact (reduced) amount needed for stoichiometric fuel mixture. This does away with the rich and lean areas associated with the over supply of fuel.
Accordingly, another object is to provide an engine device blower, or turbocharger, delivering air to multiple of such ducts, each duct supplying air to at least two of intake ports.
Further, where there are six of such ports, three manifold ducts (each receiving the same amount of air) are caused to branch so that two branches from each of the three ducts delivers air to two of the ports, respectively. Such ducts have equal lengths, and the branches also have equal (shorter) lengths.
Multiple of such cylinders, heads, pistons, and dished recesses may typically be provided in the engine, each recess having an axial cross-section of substantially parabolic shape. Such an engine may be of Diesel type or of spark combustion type, as will be seen.
If of Diesel type, the engine typically has at least one fuel injector oriented to inject fuel into the combustion zone and toward the parabolic recess, whereby combustion explosion of the injected fuel causes combustion gases to be received by that recess and to be directed generally axially, as aforesaid. The recess may then be in the piston top, in the path of injected fuel flow. Two or more of such recesses may be employed in the piston top, as will be seen.
Another object is to provide a second dished recess in the other of the piston top and head, and configured to receive and direct gases at the time of compression and combustion to flow generally axially toward said one of the piston top and head. The second recess is also typically of substantially parabolic shape in axial cross-section.
If the engine employs spark plugs for ignition, the electrodes are located in the paths of combustion gas flow from the dished parabolic recesses, as will be seen.
These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following specification and drawings, in which: